The present invention relates to improved synthetic thermoplastic resins. More particularly, the present invention relates to synthetic thermoplastic resinous compounds comprising terpolymers of styrene, sulfur dioxide, and an elastomer.
Polystyrene is one of the more versatile and widely used polymers available today. However, for many utilities, it is desirable to modify certain properties of polystyrene. This is generally accomplished by copolymerization of styrene with other materials. A particularly useful such material is the impact polystyrene which results from copolymerization of styrene and a polybutadiene rubber. Among the properties of polystyrene and, for that matter, many of its copolymers such as the impact polystyrene, which it is frequently desirable to modify are its softening point, its resistance to heat and its resistance to solvent attack.
It has been proposed in U.S. Pat. No. 2,572,185 to prepare a copolymer of sulfur dioxide and styrene. such copolymers have significantly increased heat resistance over the polystyrene alone. However, it has been found that such copolymers are not as readily moldable as would be desired. In fact, such copolymers are somewhat brittle.
It is an object of the present invention to provide a new and improved polymer composition.
Another object of the present invention is to provide a new thermoplastic terpolymer having improved properties.
Still another object of the present invention is to provide a new styrenic thermoplastic terpolymer having substantially improved heat and solvent resistance.
A remaining object of the present invention is to provide a process for the production of a new moldable styrenic terpolymer having improved properties.
Additional objects will become apparent from the following description of the invention herein disclosed.